The Letters of Arturo Toscanini, Edited and translated by Harvey Sachs

Toscanini galloped through symphonies and love affairs. Douglas Kennedy enjoys the performance

If you stroll through any book on the history of orchestral conducting, you discover that the 17th-century French composer, Jean-Baptiste Lully, is singled out as the first proper baton wielder – largely because of his infamous conducting style. It involved beating time on the floor with an ornamental wooden staff, with a steel-like point on its bottom end.

This martinet style was ideal for Lully's compositions, but it also had its physical dangers. During one such performance, Lully was beating away so vehemently that he actually stabbed himself in the foot with his sharpened staff. The wound turned septic, and a few days later, Jean-Baptiste Lully was dead of blood poisoning.

This anecdote was told to me by a musician friend in New York. I can still remember the mischievous grin that crossed his lips. It's a truth universally recognised that all orchestral musicians have a complex relationship with those highly paid gentlemen on the podium. "Four bars into a rehearsal, and we can always tell if the guy has it or if he is a charlatan," my friend said.

One thing is certain about all conductors, however: they must have the disposition of a commanding officer. And just as there can be kindly commanding officers, so too can there be the real dictators.

Which brings us to perhaps the greatest of all dictatorial conductors, Arturo Toscanini: a gentlemen who pulled no punches when it came to articulating his contempt for those collaborators who got up his nose. Consider this letter written in 1894 to a certain Giacomo Puccini, describing a rehearsal of Manon Lescaut in Pisa: "The tenor Rosati is a cretin, but he makes up for this misfortune of his with a beautiful, warm, and expressive voice." Two years later, in writing to his fiancée about a La Bohème he had just conducted, his vitriol was even more pronounced: "The other baritone ... is a real dog, and always will be".

Toscanini's contempt was not just reserved for fellow musicians. Just consider his withering condemnation of Gustav Mahler: "His music has neither personality nor genius. It is a mixture of Italianate style à la Petrella or Leoncavallo, coupled with Tchaikovsky's musical and instrumental bombast and a search for Straussian eccentricities ... without having the brilliance of the last two." Not exactly a man for the mild, reasoned position, Mr Toscanini. Then again, if this wonderfully readable collection of his letters proves anything, it's that the passion he brought to the podium was mirrored by a similar offstage intensity.

As can be gathered, The Letters of Arturo Toscanini are hugely entertaining – because, like any wildly opinionated individual, aesthetic positions spewed forth from him with scatter-gun intensity. One wonders if Toscanini's pen was way ahead of his train of thought. Throughout this fascinating compendium, you see a man caught between his deeply entrenched amour-propre, and the realisation that he could also be preposterously difficult. Both tendencies are well articulated in this 1933 letter to one of his many lovers about the Stockholm Philharmonic: "because of the immense pride of these players, who understood that they would have to play under a musician whose reputation is almost that of a pestiferous ball breaker, they have ... given the best of themselves".

Like all complex, vainglorious performers, Toscanini's libido knew no frontiers, especially since his one-and-only marriage was not a joyful liaison. But one senses from his copious letters to assorted mistresses that he also needed the frantic clandestine drama of the illicit love affair. And when it came to matters romantic, his correspondence frequently slid into the Mills & Boon school of pabulum.

Even when he was in his mid-60s, he could churn out starry-eyed prose, as shown in this letter to Elsa Kurzbauer: "How many dear memories were awakened in my soul during those days in Vienna! ... Love me even if I'm not as I was then ... I lovingly kiss your beautiful mouth."

There's no doubt that, seen retrospectively, Toscanini lived a dense life, freighted with import. He came into his own in the final years of the 19th century. His career was not only bound up in the massive changes that the new century wreaked, but also the profound catastrophe that was European fascism.

Toscanini not only spoke out against the totalitarian regimes in Germany and his native Italy, but also against the anti-Semitism which made him write to the directors of the Bayreuth Festival in 1933 withdrawing his services: "The sorrowful events [the banning of Jewish musicians in Germany] that have wounded my human and artistic feelings have not yet undergone any change, contrary to all my hopes."

This is a constantly compelling volume. It is pieced together with great narrative clarity, and with substantial footnotes, by Toscanini's biographer, Harvey Sachs. And by the end of the book, you begin to sense that, for Toscanini, all life (public and private) was a performance; all moments of self-doubt had to be tempered by the next rehearsal, the next concert, the next political argument, the next liaison interdit.

Like all hugely interesting individuals, he wore his complexities on his sleeve for all to see. And like every hyper-intelligent demagogue, he could also change his mind with great elan ... to the point where, by the end of his life, he actually started to like Mahler.